A Randomized Trial of Vaccine Adherence in Young Injection Drug Users

Each subject will receive a total of 4 immunizations over 6 months on a 0-1-2-6 month schedule. At the initial visit, subjects\>18 years of age will receive the Twinrix vaccine and subjects\<18 years of age will receive the Engerix-B vaccine. Cohort subjects\>18 years found to have HAV antibody at screening will receive Engerix-B for their remaining 3 immunizations. All subjects will receive: an immunization record with the first vaccine dose entered and the dates the next doses are due; helpful hints for remembering vaccine appointments; and written instructions on where and how to get immunized outside of SF.

Outreach worker vaccine adherence support: Half of cohort subjects will be assigned to outreach worker vaccine adherence support and will meet with their outreach workers from Haight Ashbury Youth Outreach Team (HAYOT) and Glide Health Services on the day of vaccine cohort study enrollment. Intensive vaccination tracking and in-person outreach support will begin one week before the second and third vaccine doses are due, and again two weeks before the fourth dose is due.

The Adult Immunization Clinic (AIC) is a public low-cost vaccine clinic located centrally at 101 Grove Street in the lobby of the San Francisco Department of Public Health (SFDPH). The clinic is open from Monday-Friday 9 a.m. to 4 p.m. Nurses at the AIC will be available 40 hours/week to administer free immunizations to study subjects.

Subjects randomized to a set of syringe exchange programs for administration of viral hepatitis immunizations at Month 1, 2, 6. Research nurses will provide 16 hours/week of vaccine administration services at SEPs well attended by young IDU. The San Francisco Needle Exchange (SFNE) serves primarily youth and young adults on Mondays, Wednesdays, and Fridays from 5-7 p.m. in an indoor location in the Haight-Ashbury district. A study nurse will be at SFNE for a total of 6 hours per week. HIV Prevention Project (HPP) sites also operate for 2 hrs each (Tues, Thu, Fri, Sat). Medical services are provided either in a clinic setting at indoor sites (6th Street) or at outdoor sites (Hemlock Alley, Duboce). A study nurse will attend each of these 5 weekly sites for a total of 10 hours/week.